The Write Anywhere File Layout System (WAFL)
Written by Sebastian Scholz, based on "File System Design for an NFS File Server Appliance" by Dave Hitz, James Lau & Michael Malcolm, Network Appliance, Inc.
The patented Write Anywhere File Layout
Hardware based Virtualization
No modification to Guest OS
VMM (VM monitor) or Hypervisor provides H/W resources transparently
(e.g., VMWare ESX Server, HP Integrity Server
Guest OS needs to be modified since VMM p
Dealing With TLB Tags or I Want to Build a System, What Can L4 Do for Me?
Gernot Heiser School of Computer Science and Engineering University of NSW, Sydney 2052, Australia [email protected] October 11, 2001
This paper discusses TLB tags found o
posix_thread.c /* * A pthread program illustrating how to * create a simple thread and some of the pthread API * This program implements the summation function where * the summation operation is run as a separate thread. * * Most Unix / L i nux / OS X use
CMP 426 & 697 (Operating Systems)
Additional Reference on
Multi-threading models and implementations in various Operating Systems
W. Stalling, Operating Systems: Internals and Design Principles, 7th edition, Prentice-Hall, 2012.
F. Zabatta and
fileio1.c program #include <fcntl.h> int fdrd, fdwt; char c; main(argc, argv) int argc; char *argv; cfw_ int PID; if (argc !=3) cfw_ printf("Usage: inputfile outfile\n", argv); exit(1); PID = fork(); / child is created before opening/creating files
Pre-Virtualization: Slashing the Cost of Virtualization
Joshua LeVasseur Volkmar Uhlig Ben Leslie
Matthew Chapman Gernot Heiser
University of Karlsruhe, Germany IBM T. J. Watson Research Center, New York National ICT Australia University of Ne
7.1 List three examples of deadlocks that are not related to a computersystem environment. Answer: Two cars crossing a single-lane bridge from opposite directions. A person going down a ladder while another person is
6.1 In Section 6.4 we mentioned that disabling interrupts frequently could affect the systems clock. Explain why it could and how such effects could be minimized. Answer: The system clock is updated at
Virtual Doppelg nger: On the Performance, Isolation, and Scalability of a Para- and Paene- Virtualized Systems
Stephen Soltesz*, Marc E. Fiuczynski*, Larry Peterson*, Michael McCabe+, Jeanna Matthews+ *Department of Computer Science, Princeton University
Chapter 4 Threads
Single-threaded process multithreaded process:
" " "
A thread is a basic unit of CPU utilization. Traditional process has a single thread of control. Multithreaded process can perform more than one task at a time.
Chapter 3: Processes
! ! ! ! ! !
Overview. Process Scheduling. Operations on Processes. Interprocess Communication. Examples of IPC Systems. Communication in Client-Server Systems.
The name of CPU activi
Chapter 2: OS Structures
To describe the services an operating system provides to users, processes of the system. To discuss the various ways of structuring an operating system. To explain how operating systems are installed a
Chapter 1 Introduction
Introduction to OS
What is an Operating System?
A program that acts as an intermediary between a user of a computer and the computer hardware. Various operating system goals:
Mainframe operating systems: to optimize util
NPTL TGI concept POSIX thread specification specifies that threads created from a process should share same process id. Native LinuxThread does not comply with this specification. NPTL (Native POSIX Thread Library) does not comply with this specification
The Native POSIX Thread Library for Linux
Red Hat, Inc.
Red Hat, Inc.
[email protected][email protected]
January 30, 2003
Todays demands for threads can hardly be satised by the LinuxThreads library implementing POSIX
Summary on Java Multithreading
1. Thread Concept
A program may consist of many tasks that can run concurrently. A thread is the flow of execution of a task.
In Java, you can launch multiple threads from a program concurrently
When your program executes
Summary on Monitor Implementation techniques
Wikipedia on Monitor Concept
Java Multithreading and Synchronization Mechanism Summary on OS course
Note: in this document we use process and thread interchangeably.
Monitor is neit
Chapter 10. System Calls
Operating systems offer processes running in User Mode a set of interfaces to interact with hardware devices such as the CPU, disks, and printers. Putting an extra layer between the application and the hardware has several advanta
Chapter 2 Memory Addressing Programmers casually refer to a memory address as the way to access the contents of a memory cell. But when dealing with 80 x 86 microprocessors, we have to distinguish three kinds of addresses: Logical address Included in the
General overview of the Linux file system
A simple description of the UNIX system, also applicable to Linux, is this: "On a UNIX system, everything is a file; if something is not a file, it is a process." This statement is true because there
Chapter 12. The Virtual Filesystem
One of Linux's keys to success is its ability to coexist comfortably with other systems.
You can transparently mount disks or partitions that host file formats used by
Windows , other Unix systems, or even systems with t
Kernel Module Program Examples
Get the file ModulePrograms.zip from the OS web site
Intel Architectural Support for Memory Management
The memory management facilities of the Intel Architecture are divided into two parts: segmentation and paging. Segmentation provides a mechanism of isolating individual code, data, and runtime stack memor